From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4EF20C47095 for ; Tue, 6 Oct 2020 08:56:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC9212078E for ; Tue, 6 Oct 2020 08:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726248AbgJFI4s (ORCPT ); Tue, 6 Oct 2020 04:56:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:45466 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgJFI4s (ORCPT ); Tue, 6 Oct 2020 04:56:48 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 491D6AD08; Tue, 6 Oct 2020 08:56:46 +0000 (UTC) Message-ID: <0b0de451147224657e5ac42d755c05447ee530b0.camel@suse.de> Subject: Re: INFO: task hung in hub_port_init From: Oliver Neukum To: syzbot , coreteam@netfilter.org, davem@davemloft.net, gregkh@linuxfoundation.org, gustavoars@kernel.org, ingrassia@epigenesys.com, kaber@trash.net, kadlec@blackhole.kfki.hu, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-usb@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, niklas.soderlund+renesas@ragnatech.se, pablo@netfilter.org, sergei.shtylyov@cogentembedded.com, syzkaller-bugs@googlegroups.com Date: Tue, 06 Oct 2020 10:56:40 +0200 In-Reply-To: <0000000000004831d405b0fc41d2@google.com> References: <0000000000004831d405b0fc41d2@google.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 06.10.2020, 01:19 -0700 schrieb syzbot: Hi, > HEAD commit: d3d45f82 Merge tag 'pinctrl-v5.9-2' of git://git.kernel.or.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14c3b3db900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=89ab6a0c48f30b49 > dashboard link: https://syzkaller.appspot.com/bug?extid=74d6ef051d3d2eacf428 > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=153bf5bd900000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=124c92af900000 > > The issue was bisected to: > > commit 6dcf45e514974a1ff10755015b5e06746a033e5f > Author: Niklas Söderlund > Date: Mon Jan 9 15:34:04 2017 +0000 > > sh_eth: use correct name for ECMR_MPDE bit I am afraid this has bisected a race condition into neverland. > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=152bb760500000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=172bb760500000 > console output: https://syzkaller.appspot.com/x/log.txt?x=132bb760500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com > Fixes: 6dcf45e51497 ("sh_eth: use correct name for ECMR_MPDE bit") > > INFO: task kworker/0:0:5 blocked for more than 143 seconds. > Not tainted 5.9.0-rc7-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:kworker/0:0 state:D stack:27664 pid: 5 ppid: 2 flags:0x00004000 > Workqueue: usb_hub_wq hub_event > Call Trace: > context_switch kernel/sched/core.c:3778 [inline] > __schedule+0xec9/0x2280 kernel/sched/core.c:4527 > schedule+0xd0/0x2a0 kernel/sched/core.c:4602 By this time urb_dequeue() has been killed and has returned. > usb_kill_urb.part.0+0x197/0x220 drivers/usb/core/urb.c:696 > usb_kill_urb+0x7c/0x90 drivers/usb/core/urb.c:691 > usb_start_wait_urb+0x24a/0x2b0 drivers/usb/core/message.c:64 > usb_internal_control_msg drivers/usb/core/message.c:102 [inline] > usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:153 > hub_port_init+0x11ae/0x2d80 drivers/usb/core/hub.c:4689 > hub_port_connect drivers/usb/core/hub.c:5140 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] > port_event drivers/usb/core/hub.c:5494 [inline] > This looks like it should. Which HC driver are you using for these tests? It looks like the HCD is not acting on urb_dequeue(), rather than a locking issue. Regards Oliver